Improvement in machines for mixing plaster



UrLTRDv STATES' ARCHIBALDv FORD, OF Sr. LOUIS, MISSOURI, 'ASSIGNOR or ONE-HALF HIS PATENT FjFrOR.

RIGHT TO WILLIAM L. REYNOLDS, OF SAME PLAGE.

` Y IMPROVEMENT IN I'vIAcHINI-:s FOR MIXING PLASTER.

Specification forming part of Letters Patent No. 173,401, dated February 15, 1876 application filed I JuIy 10, 1875. Y

To all'whom 'it may concern Be it known that I, ARCHIBALD FORD, a resident of St. Louis, Missouri, have invented a new and useful Improvement in Machines for Mixing Plaster, of which the following is a full, clear, and exact description, reference being hereby had to the annexed drawing, making part of this specification, in which- Figure l is an elevation, the casing and framefwork being partly in Section to show the interior construction; Fig. 2, a plan; Fig. 3, a cross-section of one of the movable arms; and Fig. 4, a cross-section of one of the xed arms. j

Like letters indicate like parts.'

To make goodplaster, the lime and sand must be thoroughly intermingled, to enable the largest quantity/possible of sand to be taken up by the lime, and the hair must be evenly distributed and interwoven with every particle of the mass. u By the ordinaryhand method this is impracticableand when it is attempted in an Ordinary mortar-mill, wherein a shaft having straight arms radiatinf.;I therel from is used, it4 is found that the hair separates, forming in wads upon the arms and shaft, clogging the machine, and, in addition, preventing the proper admixture of the sand and lime.

To obviate this difiiculty, and to provide means whereby the various ingredients can be properly compounded, is the aim ofthe present invention.

Referring to the accompanying drawing, A represents a cylindrical casing, arranged vertically, and supported on a suitable frame, B. C represents a spindle arranged vertically in the casing, and bearing on its bottom a. The spindle is provided with a series of arms, D

I p D D, &c., arranged spirally on the spindle, and projecting' horizontally therefrom. The shape of the arms is shown more distinctly in Fig. 2. Startingfrom the spindle they curve backward, and preferably to an extent of forty.

InIIIIIIIIlIII These fixed arms are also curved, but in adirection contrary to that of the movable arms D D, &c., and. this combination of xed and movable arms curving in opposite directions constitutes a peculiar feature of myinvention.

`The fixed arms and the movable'arms are so adjusted vertically, and with relation to eachx other, as to enable the latter, in their movement, to clear the former, and, as indicated in Fig. l, passing closely enough to leave but a very thin layer of the plaster between them. F represents a sweep attached to the spindle.

In operation, the lime (suitably slaked and prepared) andthe sand and hair are put into the cylinder at its top, and the spindle set in motion in the direction indicated by the arrow, Fig. 1, and so as to present the convex sides of the movable and fixed arms to each other. Owing to the shapes of the arms and the motion described, the one set of arms are drawn lengthwise vupon the other, and ,by means thereof the hair is drawn out evenly and into every part of the mixture. The contents of the mill are (partly by virtue of the bevel on the under side of the movable arms) carried downward to the bottom a of the casing, which is made convex in order to divert the contents toward the Sides of the casing, where are arranged doors G G, through which the plaster, when completed, is libera-ted.

The lowest movable arm is shaped to conform to the convexity of the bottom and scrape it. The process is practically continuous, as eight or ten revolutions of the spindle suffice to properly mix the plaster.

By this improvement plaster is made cheaply and of a very superior quality. The even and thorough introduction of the hair into the compound greatly' toughensit, and, by reason of this improved method of mixing the hair, a much larger proportion of sand can be combined with the lime, and a richer vmortar is obtained.

In a practical machine I use twenty-four revolving arms, arranged vertically in rows of six each, and twenty fixed arms arranged vertica'lly in rows of Y five each. A

I am aware of the construction shown in Patent No. 143,575, granted Hoagland and Mickel, and disclaim the same.

Having described my invention, what I G G, combined and operating substantial-ly as claim as new, and desire lno secure by Letters described. Patent is- The easing A, spindle C, arms D D D, 85e., ARCHIBALD FORD' and zums E E E,&c., all of said arms being Witnesses: curved, as shown, bottom a, the lower move WM. B. DEAN, ble arm conforming in shape thereto, and doors CEAS. D. MOODY. 

